csantiag@potpourri.UUCP (Carlos Santiago) (12/17/87)
Does anyone know what the difference is between the RADIO SHACK
hires joystick I/F and the hires joystick I/F sold with COCOMAX III?
Does anyone have a schematic for the above interfaces?
--
Gould, CSD, Home of the Firebreathers
The opinions expressed are my own.
...uunet!gould!csantiago
...mcnc!rti-sel!gould!potpourri!csantiagjejones@mcrware.UUCP (James Jones) (12/21/87)
In article <797@potpourri.UUCP>, csantiag@potpourri.UUCP (Carlos Santiago) writes: > Does anyone know what the difference is between the RADIO SHACK > hires joystick I/F and the hires joystick I/F sold with COCOMAX III? My understanding is that the CoCoMax high-res joystick interface is a real live 8-bit A/D setup, while the Radio Shack high-res joystick interface is, judging by its size, probably just a few components. I don't know the theory of operation. I do know that the one I bought from RS doesn't work--it seems to have an urge to move to the far right of the screen if it gets within a certain distance from the right edge, and there is a fairly hefty region of the screen that is very hard to move to for some reason. James Jones
knudsen@ihwpt.ATT.COM (mike knudsen) (01/13/88)
In article <579@mcrware.UUCP>, jejones@mcrware.UUCP (James Jones) writes: > My understanding is that the CoCoMax high-res joystick interface is a real > live 8-bit A/D setup, while the Radio Shack high-res joystick interface is, > judging by its size, probably just a few components Hi James, we meet again. You are right about the OLD CocoMax 1/2 interace -- it's a real A/D chip and damned handy for various other uses (sampling audio, process monitoring, ...). Zero CPU overhead. But it has two problems with the Coco 3. First, it's addressed at FF90, right where the new GIME main mode register lies. (Actually mine still worked, sicne the GIME register is W/O and the CocoMax is R/O). Second, 8 bits gives only 256 pixels, not enough for the new 320 and 640 screens. So something better was needed. Radio Shack's answer, the little $10 black box, uses an analog intergrator to convert the X-Y voltages to timing differences. Its resolution is limited only by software speed (like how fast can a 6809 count while testing a couple of bits) and easily does 640 pixels. However, it eats up a lot of CPU time. The makers of CocoMax 3 could have used the RS interface (it works great for the competing ColorMax 3 program), but redesigned their own version as a form of hardware copy protection, sorta like a "dongle." Their version looks like the RS box and is believed to work much the same, but is potted in epoxy in case you failed to get the message... Unlike the original CocoMax A/D pak, I doubt their interface is any improvement over the prior art. By now hackers must have cracked the thing, or at least patched CocoMax 3 to read the RS box. > I do know that the one I bought from RS doesn't work--it seems > to have an urge to move to the far right of the screen if it gets within a > certain distance from the right edge, and there is a fairly hefty region of > the screen that is very hard to move to for some reason. James (and everyone else) make sure you don't have a second mouse or joystick pluggged directly into the other socket while using the HiRes box. Actually the box will hose up the direct joystick more than the reverse, but anyway... If that's not the problem, your box has some out-of-tolerance caps or resistors and should be exchanged at the Shack. I've had perfect performance from mine once I figured out OS9-L2's calls to the little squeaker. > James Jones PS: James, how ya doin' with Mware's C compiler bugs/extensions? All going into OSK, or will L2 see some changes? -- Mike J Knudsen ...ihnp4!ihwpt!knudsen Bell Labs(AT&T) Delphi: RAGTIMER CIS: <memory failure, too many digits> "Just say NO to MS-DOS!"